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    <title>Document</title>
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    <script>
    // 5. 编写一个函数，返回1+2+3+5+ ... +100的和

    function sum(){
        let sum = 0
        for(let i = 1; i <= 100; i++){
            sum += i
        }
        return sum
    }

    console.log(sum());

    </script>

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